Over the past century, fossil fuels such as oil, coal and natural gas have provided a large portion of the energy utilized by the civilized world. Although increases in costs for providing these fuels have abated in the last several years, the relatively high cost of these fuels and their decreasing abundance have forced energy planners to look elsewhere for a continuing source of power to be provided to the end of this century and into th next century. Due to its virtually limitless supply and accessibility, these engineers have been directing their efforts to harnessing the energy of the sun. These efforts have resulted in the development of various devices such as flat plate collectors or solar concentrators.
The flat plate collector consists of a black plate covered by one or more transparent cover plates of glass or plastic with the sides and bottom of a box being insulated. Sunlight is transmitted through the transparent cover plates and absorbed by the black surface underneath. The plates tend to be opaque to infrared radiation and also retard convective heat transfer. The black plate heats up and in turn heats a fluid flowing under, through, or over the plate. However, it should be noted that due to this design, temperatures which are produced are below the boiling point of water.
Solar concentrators, on the other hand, may be used to produce temperatures in excess of 300.degree. F. for efficient electrical power generation, for industrial and agricultural drying and for other applications such as to increase the power output of photovoltaic cells. These concentrators usually consist of a parabolic reflector which produces a line of focus directed to a cylindrical energy absorption tube having a movable liquid therein. The heat induced in this liquid is then transferred to a boiler for direct usage or storage. However, because the temperature of the liquid bears a direct relation to the amount of sunlight focused upon the cylindrical energy absorption tube, any misalignment of the reflective surface with respect to the sun would mean that the line of focus is not exactly directed at the energy absorption tube and the amount of energy converted is lessened. Therefore, it is important that a mechanism be provided that would simply and accurately track the sun with respect to the parabolic reflector and move the reflector in conjunction with movement of the sun with respect to the reflector. It has been determined that the desert regions of the world, such as the Sahara, are expanding thereby limiting the area that people indigenous to this region can use as a food source. Part of this expansion is due to deforestation caused by the burning of wood for heat and energy. Therefore, if a solar energy collector could be produced which may be utilized by these people in place of wood, the problem of deforestation could be alleviated. However, since prior to solar tracking systems utilized an outside power source, it is imperative that a self-powered tracking system be developed which can be used in desolute areas by people not having accessibility to these power sources.